[llvm] [NVPTX] tryStoreParam - remove default-only switch statement. NFC. (PR #145948)

[Simon Pilgrim via llvm-commits]

https://github.com/RKSimon created https://github.com/llvm/llvm-project/pull/145948

#145581 remove all the remaining special cases from the switch statement leaving just the default, which MSVC complains about.

>From c0128d876e360923ff66ef9e9aa8116f86fbd80e Mon Sep 17 00:00:00 2001
From: Simon Pilgrim <llvm-dev at redking.me.uk>
Date: Thu, 26 Jun 2025 18:57:52 +0100
Subject: [PATCH] [NVPTX] tryStoreParam - remove default-only switch statement.
 NFC.

#145581 remove all the remaining special cases from the switch statement leaving just the default, which MSVC complains about.
---
 llvm/lib/Target/NVPTX/NVPTXISelDAGToDAG.cpp | 97 ++++++++++-----------
 1 file changed, 46 insertions(+), 51 deletions(-)

diff --git a/llvm/lib/Target/NVPTX/NVPTXISelDAGToDAG.cpp b/llvm/lib/Target/NVPTX/NVPTXISelDAGToDAG.cpp
index 5ee1bee49247c..7c1d13119fa18 100644
--- a/llvm/lib/Target/NVPTX/NVPTXISelDAGToDAG.cpp
+++ b/llvm/lib/Target/NVPTX/NVPTXISelDAGToDAG.cpp
@@ -1713,62 +1713,57 @@ bool NVPTXDAGToDAGISel::tryStoreParam(SDNode *N) {
   // If we have an i1, use an 8-bit store. The lowering code in
   // NVPTXISelLowering will have already emitted an upcast.
   std::optional<unsigned> Opcode;
-  switch (N->getOpcode()) {
+  switch (NumElts) {
   default:
-    switch (NumElts) {
-    default:
-      llvm_unreachable("Unexpected NumElts");
-    case 1: {
-      MVT::SimpleValueType MemTy = Mem->getMemoryVT().getSimpleVT().SimpleTy;
-      SDValue Imm = Ops[0];
-      if (MemTy != MVT::f16 && MemTy != MVT::bf16 &&
-          (isa<ConstantSDNode>(Imm) || isa<ConstantFPSDNode>(Imm))) {
-        // Convert immediate to target constant
-        if (MemTy == MVT::f32 || MemTy == MVT::f64) {
-          const ConstantFPSDNode *ConstImm = cast<ConstantFPSDNode>(Imm);
-          const ConstantFP *CF = ConstImm->getConstantFPValue();
-          Imm = CurDAG->getTargetConstantFP(*CF, DL, Imm->getValueType(0));
-        } else {
-          const ConstantSDNode *ConstImm = cast<ConstantSDNode>(Imm);
-          const ConstantInt *CI = ConstImm->getConstantIntValue();
-          Imm = CurDAG->getTargetConstant(*CI, DL, Imm->getValueType(0));
-        }
-        Ops[0] = Imm;
-        // Use immediate version of store param
-        Opcode = pickOpcodeForVT(MemTy, NVPTX::StoreParamI8_i,
-                                 NVPTX::StoreParamI16_i, NVPTX::StoreParamI32_i,
-                                 NVPTX::StoreParamI64_i);
-      } else
-        Opcode =
-            pickOpcodeForVT(Mem->getMemoryVT().getSimpleVT().SimpleTy,
-                            NVPTX::StoreParamI8_r, NVPTX::StoreParamI16_r,
-                            NVPTX::StoreParamI32_r, NVPTX::StoreParamI64_r);
-      if (Opcode == NVPTX::StoreParamI8_r) {
-        // Fine tune the opcode depending on the size of the operand.
-        // This helps to avoid creating redundant COPY instructions in
-        // InstrEmitter::AddRegisterOperand().
-        switch (Ops[0].getSimpleValueType().SimpleTy) {
-        default:
-          break;
-        case MVT::i32:
-          Opcode = NVPTX::StoreParamI8TruncI32_r;
-          break;
-        case MVT::i64:
-          Opcode = NVPTX::StoreParamI8TruncI64_r;
-          break;
-        }
+    llvm_unreachable("Unexpected NumElts");
+  case 1: {
+    MVT::SimpleValueType MemTy = Mem->getMemoryVT().getSimpleVT().SimpleTy;
+    SDValue Imm = Ops[0];
+    if (MemTy != MVT::f16 && MemTy != MVT::bf16 &&
+        (isa<ConstantSDNode>(Imm) || isa<ConstantFPSDNode>(Imm))) {
+      // Convert immediate to target constant
+      if (MemTy == MVT::f32 || MemTy == MVT::f64) {
+        const ConstantFPSDNode *ConstImm = cast<ConstantFPSDNode>(Imm);
+        const ConstantFP *CF = ConstImm->getConstantFPValue();
+        Imm = CurDAG->getTargetConstantFP(*CF, DL, Imm->getValueType(0));
+      } else {
+        const ConstantSDNode *ConstImm = cast<ConstantSDNode>(Imm);
+        const ConstantInt *CI = ConstImm->getConstantIntValue();
+        Imm = CurDAG->getTargetConstant(*CI, DL, Imm->getValueType(0));
+      }
+      Ops[0] = Imm;
+      // Use immediate version of store param
+      Opcode =
+          pickOpcodeForVT(MemTy, NVPTX::StoreParamI8_i, NVPTX::StoreParamI16_i,
+                          NVPTX::StoreParamI32_i, NVPTX::StoreParamI64_i);
+    } else
+      Opcode = pickOpcodeForVT(Mem->getMemoryVT().getSimpleVT().SimpleTy,
+                               NVPTX::StoreParamI8_r, NVPTX::StoreParamI16_r,
+                               NVPTX::StoreParamI32_r, NVPTX::StoreParamI64_r);
+    if (Opcode == NVPTX::StoreParamI8_r) {
+      // Fine tune the opcode depending on the size of the operand.
+      // This helps to avoid creating redundant COPY instructions in
+      // InstrEmitter::AddRegisterOperand().
+      switch (Ops[0].getSimpleValueType().SimpleTy) {
+      default:
+        break;
+      case MVT::i32:
+        Opcode = NVPTX::StoreParamI8TruncI32_r;
+        break;
+      case MVT::i64:
+        Opcode = NVPTX::StoreParamI8TruncI64_r;
+        break;
       }
-      break;
-    }
-    case 2:
-    case 4: {
-      MVT::SimpleValueType MemTy = Mem->getMemoryVT().getSimpleVT().SimpleTy;
-      Opcode = pickOpcodeForVectorStParam(Ops, NumElts, MemTy, CurDAG, DL);
-      break;
-    }
     }
     break;
   }
+  case 2:
+  case 4: {
+    MVT::SimpleValueType MemTy = Mem->getMemoryVT().getSimpleVT().SimpleTy;
+    Opcode = pickOpcodeForVectorStParam(Ops, NumElts, MemTy, CurDAG, DL);
+    break;
+  }
+  }
 
   SDVTList RetVTs = CurDAG->getVTList(MVT::Other, MVT::Glue);
   SDNode *Ret = CurDAG->getMachineNode(*Opcode, DL, RetVTs, Ops);